Carbonless copy forms are well known. A typical two-part form is a "manifold" (many part) construction including a top sheet having a coated back (CB) containing microencapsulated (generally colorless) dye, and a bottom sheet having a coated front (CF) containing a reactive dye-revealing substance. The top and bottom sheets are assembled, such as by gluing, into a "manifold", or many part set, which typically has a "stub". The pressure of writing on the front surface of the top sheet causes the microcapsules on the CB-coated back surface of the top sheet to rupture, releasing dye onto the CF-coated front surface of the bottom sheet, whereupon the writing is revealed in a contrasting (visible) color on the front surface of the bottom sheet.
Multiple carbonless copies are produced in a similar manner. One or more intermediate sheets are assembled (in the manifold assembly) between the CB top and CF bottom sheets. Each intermediate sheet has a carbonless front (CF) coating on its front surface for revealing the (CB) dye from the previous sheet, and has a carbonless back (CB) coating on its back surface for releasing dye to the CF-coated surface of the next sheet in the set. The intermediate sheets are termed "CFB" sheets. Using these techniques, one or more carbonless copies of information entered on the front surface of the original (top) sheet can be reproduced on the front surface of the copy (intermediate and bottom) sheets.
The chemistry of the CB (image-transferring) and CF (imagerevealing) coatings is well known, as are techniques for applying these coatings to paper stock. Generally, in order for a reaction between a CF coating and a CB coating to occur, they must be from a "common" reaction system. These coatings and techniques include various coatings applied to paper stock at the mill, as it is being produced, and coatings applied later (typically during the printing process) to plain paper stock. OPAS (On Press Application System) coatings offered by Mead Corporation are an example of the latter.
One well known variation of the two part CB/CF chemistry is the "Self-Contained" ("SC") coating. The SC coating is essentially a mixture of CB and CF, and is applied to the front surface of an underlying sheet for autogenously revealing an image of writing on the front surface of an overlying, un-coated sheet, in response to pressure rupturing micro-encapsulated (typically the CB) constituents.
Another coating is a "transfer-onto-plain-paper" coating, wherein the back side of the overlying sheet is coated and the front surface of the underlying sheet is not coated. Since this type of coating functions in conjunction with plain paper, in an autogenous manner similar to SC, but is applied to the overlying versus underlying sheet, it can be termed "anti-SC". U.S. Pat. No. 4,352,855 discloses such a "transfer-onto-plain-paper" coating.
A variation of the single sided carbonless form is found in so-called "two-way write" systems. One such example is found in U.S. Pat. No. 4,000,916, issued to Lucas, which describes a manifold report form having three superimposed record sheets (top, middle and bottom). Carbon sheets and protective sheets are arranged between the record sheets. Information entered on the front surface of the top record sheet is reproduced on the front surfaces of the middle and bottom sheets. The form is then flipped over, in its entirety, and various carbon and protective sheets are removed. Information entered on the back surface of the bottom sheet is reproduced on the back surface of the middle and top sheets.
With such two-way write systems, a true original is not formed. Rather, each of the top and bottom sheets contains "original" (e.g., hand written) information on only one surface, and "copy" (reproduced by carbon paper or the CB/CF dye reaction) information on the other surface. Such a "bifurcation" of the original information is unsuitable in many applications, such as for legal forms.
For a "true-original", two-sided self-replicating form, the top sheet would have original writing on both sides, and additional sheets would have copy images in both sides. A "true-original" is often required in legal documents, and the like.
An early example of a true-original system is found in U.S. Pat. No. 2,802,678 (Bright; 1957), wherein several sheets, interleaved carbon papers and interleaved guard sheets are employed. This patent also discloses an alternate configuration of the sheets wherein a "two-way rite" manifold assembly is produced.
Another example of a true-original system is U.S. Pat. Nos. 3,981,523, 4,036,511, RE 30,041 and RE 30,116 (Maalouf), which employ separate, non-manifolded carbonless-coated sheets.
Another example of a true-original type system is found in U.S. Pat. No. 4,126,334 (Van Malderghem), which discloses a manifold assembly of three sheets. Information is entered on one side of a top sheet, and is imaged onto corresponding one sides of an intermediate and bottom sheet. The intermediate sheet is removed from the assembly, the top sheet is flipped over, and information entered on the opposite side of the top sheet is imaged onto the corresponding opposite side of the bottom sheet.
Additional examples of "two-way rite" and "true-original" manifold form assemblies are found in U.S. Pat. Nos. 4,715,620 and 4,762,342, issued to Thompson, and are discussed in greater detail hereinbelow. As with Van malderghem, the examples set forth in the Thompson patents are also manifold assemblies, and rely on flipping the top sheet over a stub for entering information on the opposite side of the top sheet.
U.S. Pat. Nos. 4,715,620 and 4,762,342, issued to Thompson, attempt to solve the challenge of providing a "true" original where the top sheet has "original" information on the front and back surfaces thereof. Therein, top, intermediate and bottom sheets are joined in a manifold assembly having a stub. Patterned carbon papers and/or carbonless coatings are employed, between the various sheets, as in the two-way write systems. Information is entered on the front surface of the top sheet. The top sheet is then "flipped" (repositioned) around the stub so that its front surface is in contact with the back surface of the bottom sheet. Additional information is then entered on the exposed back surface of the top sheet. The front surface of the top sheet is coated with carbonless CB and the back surface of the bottom sheet is coated with carbonless CF so that the information entered on the back surface of the top sheet is reproduced on the back surface of the bottom sheet.
Using Thompson's techniques, it is extremely difficult to maintain registration (alignment) of the top sheet when it is flipped around the stub. Hence, it is suggested by Thompson that the stub be "gently folded over" along with the top sheet. This causes a gap between the top sheet and bottom sheet, which is inapposite to carbonless image forming. The top sheet, when folded over the stub in this manner, must be smoothed out prior to entering the additional information on the back surface of the top sheet. Additionally, if the stub is not folded properly, the top sheet will not be in register with the other sheets when it is flipped over for entering information on the back surface thereof.
The implementation of all of the above-described manifold assemblies (forms) is further complicated by the need for machinery necessary to collate, glue and/or staple individual, dissimilarly coated sheets of paper, carbon papers and protective sheets into a manifold arrangement. This necessitates costly set up charges for the equipment, creates delays in going from paper stock to preprinted form, and creates cumbersome inventory requirements.
Generally, any of the techniques of employing a manifold form assembly for either "two-way rite" or "true-original" systems are limited in utility in that 1) if the top sheet is to be repositioned, it is extremely difficult to maintain registration (alignment) when a stub of any kind is involved; 2) they are generally formed of many sheets of different paper stock, and require collating and assembling at the end of the production line; and 3) they are generally not very user-friendly.
The aforementioned commonly-owned U.S. patent application Ser. No. 07/334,183 discloses the "genesis" of two-sided (or duplex) copying of both sides of an original form, wherein an original part (portion) of a single sheet has information entered, such as by pen, on both sides thereof, which information is replicated on both sides of a copy part (portion) of the same single sheet. Techniques for effecting this result using carbon paper and carbonless coatings are disclosed therein.
The aforementioned commonly-owned U.S. patent application Ser. No. 07/436,189 discloses further techniques for effecting two-sided copying with a single sheet of paper, using carbonless coatings, and discloses techniques for "patterning" the carbonless coatings, and discloses techniques for making more than one copy of information entered on both sides of an original portion (panel) of a single sheet of paper.
The aforementioned commonly-owned U.S. patent application Ser. No. 07/484,686 discloses a technique wherein a single sheet of paper is divided into three panels: an original panel which is void of any carbonless coating; a copy panel which is coated with carbonless CF (image revealing) on both sides; and an intermediate transfer panel which is coated with carbonless CB (image transferring) on both sides.
The aforementioned commonly-owned U.S. patent application Ser. No. 07/494,565 discloses various techniques of patterning coatings on a single sheet of paper to avoid writing in coated areas.
The aforementioned commonly-owned U.S. patent application Ser. No. 07/497,219 discloses techniques for making two copies of information entered on both sides of an original portion of a single sheet of paper, without patterning, employing two dissimilar carbonless systems (i.e., the CB from a one system is not reactive with the CF from another system, and vice-versa).
Although all of the aforementioned commonly-owned U.S. Patent Applications disclose techniques for making duplex (two-sided) carbonless copies, using a single sheet of paper, certain improvements to those techniques have been developed by the inventors thereof.